Grok.com: "What is the best website for metal finishing questions and answers?"

finishing.com -- The Home Page of the Finishing Industry

-----

Dark streaks develop on tin plated-aluminum

I have a tin plated aluminum part that uses a copper flash intermediate. Initially, the part looks consistently tin-gray. Dark streaks have developed over time. Surface analysis shows that copper is more apparent in the dark streak areas. Does anyone have any experience with the source of the dark streaking problem? Could the tin plating have not properly bonded in this region, and over time oxidation of the copper flashing in the low-tin region starts to darken the surface appearance.

A Yerges
elect. manufacturer - Milwaukee, Wisconsin
2004

2004

Dear A Yergis,

Is your Aluminium a casting or an extrusion?

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India

Yerges.

I suppose you use a acid tin. Maybe you have a lot of contamination of copper in the tin solution. I believe your supplier has some additives to eliminate this problem.

Regards,

Anders Sundman
4th Generation Surface Engineering
Consultant - Arvika,
Sweden
2004

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories: